Hook and loop fastening systems, where the hook member typically includes a plurality of closely spaced upstanding projections with loop-engaging heads, and the loop member typically includes a plurality of woven, nonwoven, or knitted loops, are useful for providing releasable attachment in numerous applications. For example, hook and loop fastening systems are widely used in wearable disposable absorbent articles to fasten such articles around the body of a person. In typical configurations, a hook strip or patch on a fastening tab attached to the rear waist portion of a diaper or incontinence garment, for example, can fasten to a landing zone of loop material on the front waist region, or the hook strip or patch can fasten to the backsheet (e.g., nonwoven backsheet) of the diaper or incontinence garment in the front waist region.
Hook and loop fastening systems can include at least two engagement strength characteristics: peel strength and shear strength. Peel strength corresponds to the force required to disengage the fastening members from one another by peeling one fastening member upward and away from the other fastening member. Shear strength corresponds to the force required to disengage the fastening members from one another by pulling at least one of the fastening members away from the other in a plane that is parallel to the fastening members. Typically, the engagement strength of the fastening members is higher in shear than in peel.
When a user wishes to separate the hook and loop fastening members (e.g., on an absorbent article such as a diaper), typically the user peels the fastening members apart. The ease with which the fastening members can peel apart affects the user's perception of the reliability of the attachment between the fastening members. For example, when a caregiver removes a diaper from a baby, if the hook strip feels like it peels too easily from the loop landing zone or backsheet of the diaper, the caregiver may question how well the fastening members can keep the diaper closed when it is in use. And in some instances low peel strength can result in inadvertent separation of the fastening members while the diaper is being worn.
Despite the progress in hook and loop fastening technology, an enhancement in the reliability of the attachment between the fastening members, whether actual or perceived, would be desirable.